Abstract—The research of three-dimensional (3D) reservoir modeling of Alpha Zone is located in Balikpapan Formation Kutei Basin, East Kalimantan. The lithological analysis shows that Alpha Zone consists of sandstones, mudstone/shale and coal, which vertically and laterally distributed based on 206 wells and 3D seismic. Based on the results of petrophysical analysis, well and controlled correlation with seismic horizon picking, produced a pattern of fault trending NE-SW relative to the pattern trending anticline structure relative North-South, where the distributions of Alpha Zone have an average gross thickness of 9-15 meter and average net sandstone is 4-11 meter. Lithofacies approach method also used, which divided into three lithofacies sandstone, shale, and coal, which have sandstone facies distributions NW-SE, where the percentage of the distributions is 20%. The 3D reservoir modeling framework conducted is based on the reservoir depth structure maps generated from picking seismic and controlled by the correlation between wells. Distribution of reservoir properties include facies, Vshale, porosity, and water saturation (Sw), in making the property distribution is based on the analysis of the distribution wells using geostatistical variogram, where the results are validated against production data, so we will get an integrated 3D reservoir modeling of Alpha Zone. Furthermore, based on the volumetric determination of Original Oil in Place (OOIP) in Alpha Zone acquired 2.35 MMbbl.

Index Terms—geostatistical analysis, reservoir modeling, facies, petrophysic

Cite: Hariyadi, Jatmika Setiawan, Dedy Kristanto, and Nur Arief Nugroho, "Three-Dimensional Reservoir Modeling Based on Geostatistical Analysis to Determine Volumetric Oil in Place of Alpha Zone," International Journal of Geology and Earth Sciences, Vol. 7, No. 2, pp. 9-16, June 2021. doi: 10.18178/ijges.7.2.9-16